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Fueling Up During Labor

by Michele Brown

Prior to the mid-1940's, women were allowed to eat during labor. Then, a 1946 study showed that women who ate during labor had a higher chance of aspiration, (involuntary inhalation of stomach contents during anesthesia.) After the publication of the study by Curtis Mendelson, women were strongly advised that they should stop eating as soon as they felt contractions or thought that they were in labor.

Do women need to fast during labor?

Since this 1946 study, standard conventional obstetrical practice in the United States has adhered to the belief that women in labor should restrict the amount of oral and fluid intake. These concerns have been based on the presumption that potentially fatal aspiration of stomach contents, or asphyxiation, from large food particles could occur if an emergency cesarean section was warranted under general anesthesia. Recent studies in the obstetrical literature have re-evaluated this position and questioned the evidence to support this practice.

What are the actual risks of aspiration in labor?

The actual incidence of aspiration during birth is 7 per 10 million births in cases accumulated between 1979 and 1990 in the United States. A study in which 11,814 women were allowed to eat and drink during labor reported no maternal damage or death occurring from aspiration. There have been no maternal mortalities due to aspiration in Australia since 1987 and only one death in the UK in the 1990's despite a recent liberalization of oral intake policy.

Why are women in labor are more at risk to aspirate?

Pregnancy causes slowed gastric motility or action. Gastric emptying is further delayed in labor due to the use of narcotic analgesics that can predispose women to aspirate abdominal contents. In addition, the acidic nature of the stomach content can cause bronchospasm and congestion which can result in pulmonary edema and death. Certain high-risk conditions make a person more prone to aspiration, such as obesity, small airways and patients with a history of gastroesophageal reflux. Also, poor anesthesia technique can contribute to aspiration, such as blowing air into the stomach and anesthesia that is too light which may cause bucking and coughing with a full stomach and then, essentially, aspiration of the regurgitated stomach content.

What is the common philosophy that hospitals use to avoid aspiration in labor?

Intravenous hydration with Ringers lactate has been the mainstay of fluid and nutritional replacement during labor, with the occasional use of ice chips.

What are the problems associated with intravenous hydration?

Energy requirements are increased during labor, similar to an athlete doing strenuous exercise requiring increased caloric expenditure. Exclusive intravenous therapy may not be sufficient to meet these requirements. Long labors without eating can cause a woman to metabolize fats instead of carbohydrates, which can lead to a buildup of ketones which has been associated with prolonged labors.

Large infusions of glucose solutions can lead to elevated blood sugar levels in the infant, while after birth this is followed by low glucose levels, jaundice, low ph, electrolyte problems and rapid breathing. Lower dose 5% glucose solutions have been associated with greater weight loss in the infant after the first 2 days of birth. In addition, women may be more prone to fluid overload, immobilization, and increased stress when only IV fluids are used.

The restriction of oral intake and reduction of the volume of contents in the stomach prior to Cesarean section has not eliminated the reported very rare risk of aspiration. Fasting women in labor have been found to have gastric contents with more concentrated acidic content which may increase the maternal morbidity and mortality.

What can be done to eliminate the risk of aspiration in labor?

Proper anesthetic precautions should always be followed, such as avoidance of unnecessary Cesarean sections, preferential use of spinal or epidural anesthesia and protection of the airway when general anesthesia is used. Additionally, the use of medications to prevent or neutralize acid secretion in the stomach from reaching the lungs has been one of the most effective means of preventing this complication. In addition, some anesthesiologists use medications to enhance gastric emptying.

It may be best to avoid intake of solids during labor.

It may be best to consume only clear liquids, isotonic drinks and light meals, which will not increase intragastric volume and may be well tolerated.

Women who have a high risk of Cesarean section can be further restricted in their oral intake.

What are some of the official guidelines for women to follow in labor?

The World Health Organization states that women need increased energy for the requirements of labor and a woman's desire for food and liquid should not interfere with the natural process of labor and will ensure both fetal and maternal well-being. This philosophy is echoed by the WHO-Euro as well as the Society of Obstetricians and Gynecologists of Canada for women in normally progressing labors.

Summary

The pulmonary aspiration of gastric contents in labor is not a major problem in today’s obstetrical world. More evidence is now available pointing to the safety of light liquid and food regimens during labor in women who are in the low-risk population.

High-risk woman, who are more likely to need a Cesarean section should probably avoid solid foods. Anesthesiologists should administer appropriate antacids and other stomach neutralizers. They should also provide agents to promote gastric emptying before surgical procedures, with protection of the airway, should general anesthesia be required.

Dr. Brown, founder of Beauté de Maman, is a board-certified member of the American College of Obstetrics and Gynecology, a member of the American Medical Association, the Fairfield County Medical Association, Yale Obstetrical and Gynecological Society and the Women's Medical Association of Fairfield County. She is a magna cum laude graduate of Tufts University, completed her medical training at George Washington University Medical Center and completed her internship and residency in obstetrics and gynecology at Yale-New Haven Hospital. Dr. Brown has a busy obstetrical practice in Stamford, Connecticut and, as a clinical attending, actively teaches residents from Stamford Hospital and medical students from Columbia Presbyterian Hospital in New York.